But critics say the study is based on unrealistic data

Scientists at the University of Nebraska-Lincoln used a supercomputer to model the affect of removing corn material — stalks and cobs — from 128 million acres of farmland to use as a biofuel. In the study, the act of collecting the corn material produced between 50 grams to 70 grams of carbon dioxide per megajoule of biofuel energy actually produced. Over five years, the greenhouse gas emission generated during the process of converting corn material into ethanol were 7% higher than emissions from gasoline. The study also concluded that ethanol emissions would not meet greenhouse gas reduction requirements of the 2007 Energy Independence and Security Act, the Omaha World-Herald notes.

Not surprisingly ethanol-backers quickly dismissed the research. An official at DuPont (DD) said that the study strongly overestimates the amount of corn material that would be removed from farmland and the extent carbon loss experienced by farm soil as a result, the Associated Press notes.

An Environmental Protection Agency spokesperson also poured cold water on the study, saying it “does not provide useful information relevant to the life cycle greenhouse gas emissions from corn stover ethanol.”

The study in question received $500,000 in government funding. The federal government has invested close to $1 billion in cellulosic biofuels like ethanol. The study was published in the journal Nature Climate Change.